<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Gdata
 * @subpackage Gdata
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: MediaMimeStream.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Gdata_MimeFile
 */
require_once 'Zend/Gdata/MimeFile.php';

/**
 * @see Zend_Gdata_MimeBodyString
 */
require_once 'Zend/Gdata/MimeBodyString.php';

/**
 * A streaming Media MIME class that allows for buffered read operations.
 *
 * @category   Zend
 * @package    Zend_Gdata
 * @subpackage Gdata
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Gdata_MediaMimeStream {
	
	/**
	 * A valid MIME boundary.
	 *
	 * @var string
	 */
	protected $_boundaryString = null;
	
	/**
	 * A handle to the file that is part of the message.
	 *
	 * @var resource
	 */
	protected $_fileHandle = null;
	
	/**
	 * The current part being read from.
	 * @var integer
	 */
	protected $_currentPart = 0;
	
	/**
	 * The size of the MIME message.
	 * @var integer
	 */
	protected $_totalSize = 0;
	
	/**
	 * An array of all the parts to be sent. Array members are either a
	 * MimeFile or a MimeBodyString object.
	 * @var array
	 */
	protected $_parts = null;
	
	/**
	 * Create a new MimeMediaStream object.
	 *
	 * @param string $xmlString The string corresponding to the XML section
	 * of the message, typically an atom entry or feed.
	 * @param string $filePath The path to the file that constitutes the binary
	 * part of the message.
	 * @param string $fileContentType The valid internet media type of the file.
	 * @throws Zend_Gdata_App_IOException If the file cannot be read or does
	 * not exist. Also if mbstring.func_overload has been set > 1.
	 */
	public function __construct($xmlString = null, $filePath = null, $fileContentType = null) {
		if (! file_exists ( $filePath ) || ! is_readable ( $filePath )) {
			require_once 'Zend/Gdata/App/IOException.php';
			throw new Zend_Gdata_App_IOException ( 'File to be uploaded at ' . $filePath . ' does not exist or is not readable.' );
		}
		
		$this->_fileHandle = fopen ( $filePath, 'rb', TRUE );
		$this->_boundaryString = '=_' . md5 ( microtime ( 1 ) . rand ( 1, 20 ) );
		$entry = $this->wrapEntry ( $xmlString, $fileContentType );
		$closingBoundary = new Zend_Gdata_MimeBodyString ( "\r\n--{$this->_boundaryString}--\r\n" );
		$file = new Zend_Gdata_MimeFile ( $this->_fileHandle );
		$this->_parts = array ($entry, $file, $closingBoundary );
		
		$fileSize = filesize ( $filePath );
		$this->_totalSize = $entry->getSize () + $fileSize + $closingBoundary->getSize ();
	
	}
	
	/**
	 * Sandwiches the entry body into a MIME message
	 *
	 * @return void
	 */
	private function wrapEntry($entry, $fileMimeType) {
		$wrappedEntry = "--{$this->_boundaryString}\r\n";
		$wrappedEntry .= "Content-Type: application/atom+xml\r\n\r\n";
		$wrappedEntry .= $entry;
		$wrappedEntry .= "\r\n--{$this->_boundaryString}\r\n";
		$wrappedEntry .= "Content-Type: $fileMimeType\r\n\r\n";
		return new Zend_Gdata_MimeBodyString ( $wrappedEntry );
	}
	
	/**
	 * Read a specific chunk of the the MIME multipart message.
	 *
	 * @param integer $bufferSize The size of the chunk that is to be read,
	 * must be lower than MAX_BUFFER_SIZE.
	 * @return string A corresponding piece of the message. This could be
	 * binary or regular text.
	 */
	public function read($bytesRequested) {
		if ($this->_currentPart >= count ( $this->_parts )) {
			return FALSE;
		}
		
		$activePart = $this->_parts [$this->_currentPart];
		$buffer = $activePart->read ( $bytesRequested );
		
		while ( strlen ( $buffer ) < $bytesRequested ) {
			$this->_currentPart += 1;
			$nextBuffer = $this->read ( $bytesRequested - strlen ( $buffer ) );
			if ($nextBuffer === FALSE) {
				break;
			}
			$buffer .= $nextBuffer;
		}
		
		return $buffer;
	}
	
	/**
	 * Return the total size of the mime message.
	 *
	 * @return integer Total size of the message to be sent.
	 */
	public function getTotalSize() {
		return $this->_totalSize;
	}
	
	/**
	 * Close the internal file that we are streaming to the socket.
	 *
	 * @return void
	 */
	public function closeFileHandle() {
		if ($this->_fileHandle !== null) {
			fclose ( $this->_fileHandle );
		}
	}
	
	/**
	 * Return a Content-type header that includes the current boundary string.
	 *
	 * @return string A valid HTTP Content-Type header.
	 */
	public function getContentType() {
		return 'multipart/related;boundary="' . $this->_boundaryString . '"' . "\r\n";
	}

}
